As a method for forming a thin film, such as a silicon oxide film (SiO2) or a silicon nitride film (Si3N4), on a substrate at a low temperature, a method of alternately supplying a process gas (silicon-containing gas or the like) or a reactive gas (oxygen- or nitrogen-containing gas or the like) into a process chamber may be used. In this instance, a method for forming a film at a low temperature of 200° C. or less by supplying a catalyst into the process chamber may be used.
In Japanese Unexamined Patent Application Publication No. 2010-219500, a SiO2 film forming sequence is disclosed as a typical example of a thin film. In the film forming sequence, a silicon-containing gas and a catalyst are supplied to a substrate accommodated in a process chamber, the silicon-containing gas remaining in the process chamber is removed, an oxygen-containing gas and a catalyst are supplied to the substrate, and then the oxygen-containing gas remaining in the process chamber is removed, thereby forming a SiO2 film on the substrate. Using the film forming sequence as one cycle, the SiO2 film having a desired film thickness may be obtained by repeating the film forming sequence a predetermined number of times.